Semiconductor wafers such as silicon wafers having different thicknesses, which are sufficiently mechanically stable for handling, are used for manufacturing of semiconductor devices and integrated circuits. In most cases, comparably thick wafers are needed mainly for mechanical reasons during manufacturing but not for the final devices.
For many applications, for example electronic components such as fast-switching CMOS circuits, parasitic electrical coupling of the individual devices of the circuit to the large semiconductor volume of the wafer may result in unwanted coupling between individual devices and can limit the switching speed. Therefore, silicon-on-insulator (SOI) wafers are often employed. Such wafers include a buried oxide layer which electrically insulates the silicon layer used for forming the devices from the remaining semiconductor substrate. However, SOI-wafers are comparably expensive.
On the other hand, thin monocrystalline semiconductor wafers are desired for many applications such as devices for chip cards or devices where the current path goes from the top surface to the bottom surface. For such thin wafers additional carriers are needed for mechanical reason during processing. Although the additional carriers improve the mechanical stability, additional costs incur. Furthermore, the carriers often tolerate only moderate processing conditions to which the semiconductor wafers are subjected and therefore limit their application.
For example carriers such a glass carriers glued to semiconductor wafers are often limited to temperatures below 350° C. due to the limited thermal stability of the adhesive. Glass carriers are also prone to breaking so that care must be taken during low pressure and vacuum processes. On the other hand, expensive SOI carrier system can withstand high temperatures but their manufacturing, particularly the bonding processes of partially or completely processed wafers are technologically difficult.